Needle guard

ABSTRACT

A needle guard assembly having a resilient arm extending from a base situated to slide along the shaft of a needle, In one implementation the needle guard has an elongate containment member that rides with the resilient arm and is co-operable with the resilient arm to effectuate a covering of the entire distal tip of the needle upon the needle being refracted into the needle guard.

FIELD

The inventions disclosed herein relate to safety needle devices.

BACKGROUND

A number of U.S. Patents describe safety IV catheters where the distaltip of the needle is provided with a degree of protection after use,including but not limited to: McLees, U.S. Pat. No. 5,135,504; Erskine,U.S. Pat. No. 5,797,880; Woehr, et al., U.S. Pat. No. 6,287,278;Bialecki, et al., U.S. Pat. No. 6,652,486; McGurk, U.S. Pat. No.7,291,130; Rhad, et al., U.S. Pat. No. 7,303,548; Menzi, et al., U.S.Pat. No. 7,731,687; and Harding, et al., U.S. Pat. No. 7,828,774.

These prior art safety catheters all exhibit one or more drawbacks thatcould potentially place healthcare workers, or others at risk for apercutaneous or non-percutaneous blood or bodily fluids exposure afterthe needle tip is covered by the safety mechanism. Although the needletip itself is covered after use on a number of available safety IVcatheters, the entirety of the needle tip is not fully contained afteruse which could result in blood or fluid residing in the distal end ofthe needle lumen leaking, or otherwise escaping, into the workplace andcontacting a healthcare provider. For example, splattered blood couldenter a mucous membrane region of the eyes, nose or mouth of anyhealthcare personnel within close proximity to the splatter. Theexposure should then be reported and post exposure treatment,prophylaxis and follow up would occur, incurring costs to theinstitution and worry to the individual exposed to the blood.Additionally, some commercially available needle guards can be easilydefeated by an inadvertent incident where the components no longerprotect or shield the contaminated tip.

FIGS. 1-5 illustrate a safety needle guard 10 similar to the onedisclosed in U.S. Pat. No. 6,287,278. The needle guard 10 is constructedfrom a single piece of material as shown in FIG. 1 and formed to assumethe configurations depicted in FIGS. 2-5 during use. FIGS. 2 and 3 showdifferent side views of the needle guard 10 in a ready position wherethe distal tip 18 of the needle 15 is unprotected. FIGS. 4 and 5 showthe different side views of the needle guard 10 after the needle guardhas been activated to cover the distal tip 18. As shown in FIGS. 4 and5, although the extreme distal tip 18 of needle 15 is protected, theopen lumen 17 in the bevel region 16 of the needle remains exposed.Another problem associated with the needle guard 10 is that forces maybe applied to the needle guard arms 11 and 12 at locations to cause thedistal arm segments 13 and 14 to be urged outward. This creates a riskof having the distal arm segments 13 and/or 14 being moved away fromprotecting the distal tip 18.

SUMMARY

According to some implementations an intravenous (IV) catheter assemblyis provided comprising: a catheter hub comprising a hollow body having aproximal end and a distal end, the hollow body defining an interiorspace; a catheter having a proximal end and a distal end, the proximalend of the catheter coupled to the proximal end of the catheter hub; aneedle having a needle shaft and a distal tip, the needle moveablebetween a ready position and a retracted position, in the ready positionthe distal tip of the needle extending distally from the distal end ofthe catheter, in the retracted position the distal tip of the needleresiding in a position proximal to the proximal end of the catheter, theneedle shaft having a change in profile; and a needle guard comprisingan arm that extends distally from a base having an aperture formedtherein, the needle guard slideably mounted on the needle shaft with theneedle shaft passing through the aperture formed in the base, theaperture sized to engage with the change in profile of the needle shaftto limit the proximal movement of the needle with respect to the needleguard, the arm comprising a resilient material and having a proximalsection, a mid-section and a distal section, the distal section of thearm resides and is urged against a side of the needle shaft when theneedle is in the ready position, the needle guard further comprising anelongate member having a through passage extending between a proximalend and a distal end of the elongate member, the elongate memberextending distally from a position at or near the base and slideablealong the needle shaft as the needle is moved between the ready positionand the retracted position, the elongate member having a length suchthat substantially coincident with the change in profile engaging theaperture in the base the entirety of the distal tip of the needle ispositioned to reside within the through passage of the elongate memberand the distal section of the arm disengage with the needle shaft tomove radially inward to at least partially cover the distal end of theelongate member, the elongate member being sufficiently rigid torestrict longitudinal movement of the needle with respect to the needleguard when the distal section of the arm at least partially covers thedistal end of the elongate member.

According to other implementations an IV catheter assembly is providedcomprising: a catheter hub comprising a hollow body having a proximalend and a distal end, the hollow body defining an interior space; acatheter having a proximal end and a distal end, the proximal end of thecatheter coupled to the proximal end of the catheter hub; a needlehaving a needle shaft and a distal tip, the needle moveable between aready position and a retracted position, in the ready position thedistal tip of the needle extending distally from the distal end of thecatheter, in the retracted position the distal tip of the needleresiding in a position proximal to the proximal end of the catheter, theneedle shaft having a change in profile; and a needle guard comprisingfirst and second arms that extend distally from a base having anaperture formed therein, the needle guard slideably mounted on theneedle shaft with the needle shaft passing through the aperture formedin the base, the aperture sized to engage with the change in profile ofthe needle shaft to limit the proximal movement of the needle withrespect to the needle guard, each of the first and second armscomprising a resilient material and having a proximal section, amid-section and a distal section, the first and second arms extendingfrom different positions of the base and intersecting one another alongtheir mid-sections so that the distal sections of the first and secondarms reside and are urged against opposite sides of the needle shaftwhen the needle is in the ready position, the needle guard furthercomprising an elongate member having a through passage extending betweena proximal end and a distal end of the elongate member, the elongatemember extending distally from a position at or near the base andslideable along the needle shaft as the needle is moved between theready position and the retracted position, the elongate member having alength such that substantially coincident with the change in profileengaging the aperture in the base the entirety of the distal tip of theneedle is positioned to reside within the through passage of theelongate member and the distal section of at least one of the first andsecond arms disengages with the needle shaft and moves radially inwardto at least partially cover the distal end of the elongate member, theelongate member being sufficiently rigid to restrict longitudinalmovement of the needle with respect to the needle guard when the distalsection of at least one of the first and second arms at least partiallycovers the distal end of the elongate member.

According to some implementations the needle guard comprises a unitarystructure with the elongate member being integrally formed with the baseof the needle guard.

According to some implementations the needle is stopped in the retractedposition by component or feature incorporated with, or otherwisesituated, at or near the distal end of the elongate member.

According to some implementations a proximal section of the elongatemember comprises a reduced diameter portion and/or a frustoconicalportion useable to assist in self-centering the needle on the needleguard.

Many other implementations are disclosed and contemplated herein.Moreover, it is important to note that the inventions are not limited tosafety IV catheters, but are applicable to any of a variety of needleproducts.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 through 5 illustrate a prior art needle guard;

FIGS. 6A through 6C illustrate implementations of a flat stock usable toform needle guards disclosed and contemplated herein;

FIGS. 7 through 10 illustrate a needle guard assembly according to oneimplementation:

FIGS. 11 through 17 illustrate protective elongate members according tovarious implementations;

FIGS. 18 and 19 illustrate a needle guard assembly according to anotherimplementation:

FIGS. 20 through 23 illustrate a needle guard assembly according toanother implementation:

FIG. 24 illustrates a needle guard assembly according to anotherimplementation:

FIGS. 25A-D illustrate needle guard elongate members according variousimplementations;

FIGS. 26 through 31 illustrate a needle guard assembly according toanother implementation:

FIGS. 32 through 34 illustrate a needle guard assembly according toanother implementation:

FIGS. 35 through 37 illustrate a needle guard assembly according toanother implementation:

FIG. 38 illustrates a safety intravenous catheter assembly according toone implementation:

FIGS. 39 and 40 illustrate a safety intravenous catheter assemblyaccording to another implementation:

FIG. 41 illustrates a needle guard assembly according to anotherimplementation.

DETAILED DESCRIPTION

FIGS. 6 through 11 illustrate needle guards 100 according to someimplementation. According to one implementation, a first portion 110 ofthe needle guard 100 is manufactured from a flat material havingresilient characteristics, as shown in FIG. 6A or 6B, and shaped toassume the in-use configurations shown in FIGS. 7-10, whereas a secondportion 150 (see FIGS. 11 and 12) of the needle guard 100 defines anelongate member 152 having a through passage 153 extending between aproximal end 154 and an distal end 156. FIGS. 7 and 8 show differentside views of the needle guard 100 situated in a first axial position ona needle 130 with the distal end 134 of the needle being unprotected.FIGS. 9 and 10 show the different side views with the needle guard 100situated in a second axial position on the needle 130 with the distalend 134, including the entirety of the bevel 136, being protected.

In one implementation, the first portion 110 of the needle guard 100 hasfirst and second resilient arms 101 and 102, respectively, with each ofthe arms comprising a proximal section 103,104, a mid-section 105, 106and a distal section 107, 108. The first and second arms 101, 102 extenddistally from different positions of a base 118 and intersect oneanother along their mid-sections 105, 106 so that lip segments 111, 112of the distal sections 107, 108 reside at and are urged against oppositesides of the needle shaft 131 when the needle guard is situated in thefirst axial position. The first portion 110 of the needle guard 100 isslideably mounted on the needle shaft 131 with the needle shaft passingthrough an aperture 119 formed in the base 118. In one implementationthe aperture 119 is sized to engage with a change in profile 132 on theneedle to limit movement between the needle 130 and the needle guard 100in a first direction when the needle guard 100 is situated in the secondaxial position. The change in profile 132 may comprises a crimp on theneedle shaft 131 or any other form of enlargement such as those depictedin FIGS. 33 and 35.

As shown in FIG. 7, the elongate member 152 is situated in the needleguard 100 with its proximal end 154 positioned at or near the base 118,and with its distal end 156 positioned at or near lip segment 111 of arm101 when the needle guard is in the ready position. In someimplementations the elongate member 152 is substantially coaxial withthe needle 130 with the diameter or cross-sectional area of the throughpassage 153 being sufficiently large to permit the elongate member toslide over the change in profile 132. In other implementations theelongate member 152 is substantially coaxial with the needle 130 withthe diameter or cross-sectional area of all or a proximal portion of thethrough passage 153 being smaller than a cross-sectional area of thechange in profile 132. In implementations where all or a portion of thethrough passage 153 has a cross-sectional area smaller than across-sectional area of the change in profile 132, the through passage153 is made to be expandable over the change in profile 132, like, forexample that shown in FIG. 9. In some implementations the sections ofthe elongate member 152 where the through passage 153 has a smallercross-sectional area than the change in profile 132 are resilient tocause the cross-sectional area of the through passage 153 to contractinwardly after that portion of the through passage has crossed thechange in profile. In some implementations, as discussed in more detailbelow, only a proximal portion of the expandable member 152 has areduced cross-sectional area that is resiliently expandable over thechange in profile 132. In use, the elongate member 152 travels axiallyalong the shaft of the needle in conjunction with the first portion 110of the needle guard 100. In some implementations the elongate member 152rides with the first portion 110 of the needle guard with the proximalend 154 abutting the base 118. In other implementations the proximal end154 of the elongate member 152 is attached to base 118. In otherimplementations, a proximal portion or all of the elongate member 152 isintegral with the base 118.

FIGS. 9 and 10 show the needle guard 100 positioned on the needle 130 inthe second axial position with the needle tip 134, including theentirety of the bevel 136, being covered. In one implementation, as theneedle guard is advanced over the needle 130 and the lip segments 111and 112 are moved distal to the needle tip 134, the needle guard 100 isstopped in the second axial position by the engagement of the change inprofile 132 on the needle with the aperture 119 of base 118. Other stopimplementations are disclosed below. The length of the elongate member152 is selected so that substantially coincident with the change inprofile 132 engaging, for example, the aperture 119 in base 118 theentirety of the distal tip 134 and bevel region 136 of needle 130 ispositioned to reside within the through passage 153 and so that at leastone of the distal sections 107, 108 of arms 101, 102 disengage with theneedle to fully or at least partially cover the distal end 156 of theelongate member 152.

In one implementation, as shown in FIG. 7, the distal section 107 of arm101 is configured to assume a first angle with respect to the needleaxis when the needle guard 100 is positioned in a ready position and thedistal section 108 of arm 102 is configured to assume a second anglewith respect to the needle axis when the needle guard 100 is positionedin the ready position, the second angle being greater than the firstangle. Further, as shown in FIG. 9, when the needle guard 100 is in thesecond axial position the distal section 107 of arm 101 is oriented andbiased to assume a substantially perpendicular relationship with respectto the longitudinal axis of the elongate member 152. In someimplementations the cross-sectional area of the distal section 107 issufficient to cover the entirety of the distal end 156 of the elongatemember 152. In other implementations, less than the entirety of thedistal end 156 of the elongate member 152 is covered by distal section107.

As mentioned above, the distal end 107 of arm 101 may be biased so thatit applies a downward/proximally acting force on the distal end 156 ofelongate member 152 when the needle guard 100 assumes the second axialposition. In one implementation the bias is created by a resilient hingein the region 117. The application of a downward/proximally acting forceassists in the formation of a full or partial seal that may impede orprevent contaminants within the needle 130 and elongate member 152lumens from leaking out of the needle guard 100 after it has assumed thesecond axial position. In some implementations, the distal end 108 ofarm 102 is oriented and biased to assume an oblique angle with respectto the distal end 107 and to exert a force on the distal end 107 in adirection toward the distal end 156 of elongate member 152.

In implementations where the needle guard 100 forms a part of anintravenous catheter 700, as shown in FIG. 38, protrusions 117 and 116may be formed on arms 101 and 102, respectively, to engage with one ormore features 703 in the interior of the catheter hub 702 to releasablysecure the needle guard 100 in the catheter hub when the catheterassembly 700 is in a ready position.

As mentioned above, a problem associated with prior art spring clipneedle guard devices is that forces may be applied to parts of thespring clip arms to cause the distal arm sections to be urged outward.This creates a risk of the distal arm sections being moved away fromprotecting the needle tip after the needle guard has assumed a protectedposition. To address the problem, in some implementations the firstportion 110 of the needle guard 100 comprises straight, or substantiallystraight, arm segments 113 and 114 that are disposed proximal to distalarm sections 107 and 108, respectively. As shown in FIG. 9, the armsegments 113 and 114 are arranged so that when the needle guard 100assumes the second axial position on the needle 130, the arms segments113 and 114 abut and are laterally disposed on opposite sides of theouter surface of the elongate member 152. Arm segments 113 and 114 aredisposed to occupy positions between the distal sections 107, 108 andthe intersection point 126 of the arms 101 and 102 when the needle guardis in the second axial position. In one implementation arm segments 113and 114 are located adjacent to distal sections 107 and 108,respectively, and disposed a distance distal to the intersection point126 of the arms 101 and 102. In one implementation the distance (D₁)segment 113 is distally spaced from the intersection point 126 isgreater than or equal to L₁ sin β3, with L1 being the approximatedistance between the intersection point 126 and the location arm 101intersects the outer circumference of the elongate member 152 and βbeing the angle between arm 101 and a line running perpendicular to thelongitudinal axis of elongate member 152 at the intersection point 126.Although not required, segment 114 is preferably distally spaced fromthe intersection point 126 so to be substantially longitudinally alignedwith segment 113.

In some implementations segments 113 and 114 have substantially the samewidth as distal sections 107 and 108, respectively. In otherimplementations segments 113 and 114 have widths that are less thanthose of distal sections 107 and 108, respectively, as shown in FIG. 6B.In other implementations, one or both of segments 113 and 114 maycomprise arcuate portions that at least partially conform to portions ofthe outer curvature of the elongate member 152. An advantage of such aconfiguration is that the at least partial conformability of segments113, 114 with the outer surface of elongate member 152 acts to stabilizethe segments about the elongate member in the event improper forces areapplied to either or both of arms 101 and 102. In other words, the atleast partial conformability reduces the likelihood of arms 101 and/or102 slipping sideways on the outer surface of elongate member 152 whenimproper forces are applied to arms 101 and/or 102. As an example, andwith reference to FIG. 6A, the outer edges 121 and 122 of segments 113and 114 may be curved inward along cut-lines 123 and 124, respectively,to assume a partially curved configuration.

The first portion 110 and second portion 150 of the needle guard 100 mayassume any of a variety of configurations. Turning again to FIGS. 6A and6B, in one implementation the arm mid-sections 105 and 106 are narrowedsufficiently to accommodate the elongate member 152 with a clearanceexisting between the mid-sections 105 and 106 and the outer surface ofthe elongate member when the first portion 110 is formed into a springclip as exemplified in FIGS. 7-10. The dotted lines in FIGS. 6A and 6Bdepict folding locations for producing bends and/or hinges during thespring clip fabrication process.

In some implementations the elongate member 152 comprises one or morematerials having sufficient rigidity to resist buckling during use. Theone or more materials may comprise any of a variety or composition ofmaterials, such as for example, a metal, an elastomer/plastic, a braidedstructure, a random stranded structure, combinations thereof, etc.Elongate member 152 may comprise a plurality of portions or sectionsjoined together to form the elongate member.

Elongate member 152 may be fabricated, for example, utilizing adeep-draw fabrication process where a metal is work hardened during thedrawing process, thus eliminating the need for secondary heat-treatingon the finished part. Elongate member 152 may also comprise, forexample, an extruded portion of elastomer/plastic tubing.

According to some implementations, the through passage 153 in a proximalportion of the elongate member 152 adjacent or near the base 118 has areduced cross-sectional area/diameter that causes the proximal portionof the through passage 153 to engage with the change in profile 132 onthe needle shaft 131. In one implementation the reduced diameter portionof the through passage 153 acts as stop, in lieu of aperture 119 in base118, to limit movement of the needle guard 100 on the needle 130 to thesecond axial position. In other implementations a reduced diameterbushing or sleeve may be positioned at or coupled with the proximal end154 of the elongate member 152 to act as a stop.

According to other implementations, the proximal portion of the elongatemember 152 comprises a material that is capable of expanding or flexingover the change in profile 132 in a manner depicted in FIG. 9. In oneimplementation the proximal portion of the elongate member comprises aresilient material that permits it to expand over the change in profile132 while at the same time exerting a constraining/radial force on thechange in profile 132. An advantage of such implementations is that theradial constraining force applied to the change in profile 132 acts tolimit lateral movement of the elongate member 152 after the needle guard100 has been positioned to cover the distal end of the needle. This isparticularly advantageous when a full or partial seal between the distalsection 107 or arm 101 and the distal end 156 of elongate member 152 isdesired. According to other implementations the entirety of elongatemember 152 comprises a flexible material that allows the elongate memberto expand or flex over change in profile 132 of the needle 130 as theelongate member is slid or moved to the distal end of the needle.

FIG. 13 is a cross sectional side view of an implementation of elongatemember 152 having a reduced inner diameter proximal portion 155. Theelongate member 152 may also have an absorbent or porous innercoating/membrane/liner or the like 158 sized to contact the outerdiameter of needle 130 and absorb or wipe blood or bodily fluids fromthe exterior surface of the needle as the needle slides or moves throughthe elongate member. The absorbent or porous member 158 may also absorbblood or bodily fluids that reside in the needle lumen. In someimplementations the absorbent or porous member 158 includes amedication, such as, for example, an antimicrobial or antibiotic agent.

FIG. 14 is a cross sectional side view of an implementation of elongatemember 152 comprising a reduced diameter or frustoconical portion 159 atits proximal end 154 and a distal flange 157 at its distal end 156.According to one implementation the distal flange 157 provides a largercontacting surface 179 to facilitate the formation of a seal between thedistal section 107 of arm 101 and the distal end 156 of the elongatemember when the needle guard is positioned in the second axial positionon the needle 130. In other implementations the distal flange 157 andthe lip 111 of arm 101 are constructed so that upon the needle guard 100assuming the second axial position on the needle 130 the lip 111 engageswith the flange 157 to help secure the distal section 107 of arm 101 tothe distal end 156 of elongate member 152. In such implementations, thedistal flange 157 may be annular, continuous or segmented.

FIG. 15 is a cross sectional view of an implementation of elongatemember 152 comprising a proximal section having a reduced diameter orfrustoconical portion 160 transitioning to a reduced diameter endsection or sleeve 161. The elongate member 152 may also comprise adistal flange 157. In one implementation the proximal end section 161 isused for attaching the proximal end of the elongate member 152 to thebase 118. Attachment may be accomplished via stamping, pressing or othermechanical fastening processes. For example, the proximal section 161may be segmented to form tabs, or the like) that are fixed into aperture119 or other openings provided in the base 118. In other implementationsthe shape and size of the proximal section 161 permits it to be pressfitted into aperture 119. It is important to note that any of a varietyof other attachment methods, or combination of methods, may be used toattach the elongate members 152 disclosed and contemplated herein to thebase 118 of the needle guard. These methods may include the use ofadhesives, soldering, welding, mechanical attachment, etc. As will bediscussed in more detail below, in some implementations the elongatemember 152 is unitarily formed with the first portion 110 of the needleguard 100.

An advantage of providing areas/sections of reduced diameter along alength of the elongate member 152 is that these areas/sections assist inmaintaining the elongate member coaxially disposed on the needle 130which reduces friction or drag forces that may otherwise exist as theelongate member 152 is moved along the needle shaft 131. They alsoassist in urging or maintaining the elongate member 152 in a coaxialrelationship with the needle shaft 131.

FIG. 16 is an isometric view of an implementation of an elongate member152 having an enlarged diameter distal portion 164 and a small diameterproximal portion 163. FIG. 17 is a cross sectional view of oneimplementation of an elongate member according to FIG. 16 comprising aninner ring or bushing 165 retained within the cavity of the enlargeddiameter portion 164 that is situated to concentrically locate theneedle 130 within the elongate member 152 and to wipe blood or bodilyfluids from the exterior surface of the needle 130 as the needle slidesor axially moves through the elongate member 152. One advantage of theenlarged diameter distal portion 164 is that it provides a reservoir forcollecting blood or bodily fluids wiped from the exterior surface of theneedle and/or that emanate from the lumen of the needle. In oneimplementation the reservoir contains a coating or material forabsorbing the blood or bodily fluids. In one implementation theabsorbent material occupies all or a substantial portion of thereservoir and is deformable or pierceable to accommodate an introductionof the distal end of the needle into the reservoir region of theelongate member. In implementations where a seal is provided between thedistal end of the elongate member and the distal arm section 107, one ormore apertures may be provided in the wall of the reservoir to inhibitthe formation of a hydraulic lock. In one implementation the one or moreapertures in the wall of the reservoir are sufficiently small to preventor inhibit blood or bodily floods from passing there through.

In some implementations an internal or external sealing member isprovided at or near the proximal end 154 of the elongate member.

In other implementations the elongate member 152 comprises one or moreencapsulated annular rings, ribs or segments that deform or flex overthe change in profile 132 as the needle guard 100 is advanced over theneedle 130. In some implementations the elongate member 152 compriseselongate encapsulated portions that extend along all or a portion of thelength of the elongate member. In such implementations the encapsulationstructures may be formed by use of an extrusion process. Theencapsulated members may comprise chemical substances that are caused tointeract with one another as the one or more encapsulated members expandover the change in profile 132 and to solidify to lock the proximal end154 of the elongate member 152 onto the change in profile 132 of theneedle 130.

As discussed above, it may be desirable to form a partial or full sealat the intersection of the distal section 107 of arm 101 and the distalend 156 of the elongate member 152 when the needle guard 100 ispositioned in the second axial position. According to someimplementations, the inner surface of distal section 107 is coated orlaminated with a material, compound or agent conducive to forming a sealwith the distal end 156 of the elongate member 152 when the distalsection 107 comes into contact with distal end 156. Conversely, or inconjunction with coating or laminating the inner surface of distal armsection 107, the distal end 156 of elongate member 152 may also becoated or laminated with a material, compound or agent conducive toforming a seal. For example, in some implementations one or both ofdistal section 107 and distal end 156 comprise a formable material, suchas an elastomer, for effectuating a full or partial seal between themembers. Other examples include coating, laminating, or otherwisetreating one or both of the contact surfaces with a tacky substance oradhesive. Other examples may include the fixation of an elastomer 0-ringon the distal end 156 of the elongate member 152 so that at least aportion of the 0-ring extends distal to the end 156 so that it may matewith a contact surface of distal arm section 107. Other sealing methodsare also contemplated.

FIGS. 18 and 19 show a needle guard 200 according to anotherimplementation. The needle guard 200 is similar to that of needle guard100 described above except that arm 102 terminates at segment 114 whereit is attached to the outer surface of the elongate member 152. In oneimplementation, segment 114 is curved to produce an attachment surfacethat is the same as or approximates the curvature of the outer surfaceof the elongate member 152. In substantially all other respects theimplementations of the first portion 110 and the second portion 150 ofthe needle guard 200 function in the same way to effectuate a coveringof the distal end of the needle 130 as described above. It is importantto note that arm 102 may be fixed to the outer surface of the elongatemember 152 at more proximally located sites. For example, arm 102 maycomprise a shorter length with an end portion of the arm 102 beingattached anywhere along the length of the elongate member 152. In otherimplementations arm 102 is eliminated altogether with the distal end 154of the elongate member 152 being firmly coupled to the base 118.

According to other implementations the first portion 110 and theelongate member 152 of the needle guard 100 are unitarily constructed.In one implementation this accomplished by subjecting the base 118 ofthe needle guard to a deep drawing process to form the elongate member152. In this manner, the elongate member 152 may be described as beingco-extensive to the aperture 119 in the base 118. According to oneimplementation the unitary construction process begins with theformation of a metal strip 50 as shown in FIG. 6C having an area 52designated to form the base 118 of the needle guard 100. In someimplementations the metal strip 50 has a uniform thickness, while inothers the strip 50 is provided with an enhanced thickness dimension atleast in the region 54 where the deep drawing process is to be appliedto form the elongate member 152. In some implementation the arm sections101 and/or 102, as shown, for example in FIG. 6A, are formed prior todeep drawing the elongate member 152, while in other implementations thearm sections 101 and/or 102 are formed after the formation of theelongate member 152. In some implementations the fabrication processbegins with a metal sheet having a uniformed and enhanced thicknessdimension which is followed by a process that results in the flatteningof the metal sheet in the areas 56 and 58 where the arms 101 and/or 102are designated to reside. The flattening process may occur before orafter the formation of the elongate member 152 by use of the deepdrawing process. In conjunction with or after the flattening process toproduce one or more areas of a reduced thickness, at least a portion ofthe reduced thickness areas are cut to produce at least a portion ofarms 101 and/or 102.

With reference to FIGS. 13 through 17, one or more of the features 155,159, 160, 161, 163 and 164 may be formed into the elongate member 152during the deep drawing process by the use of one or multiple diesdimensioned and shaped to form the one or more features. For example, inone implementation the frustoconical portion 160 and reduced diameterend section 161 of the elongate member 152 is formed during the drawingprocess. An advantage of incorporating one or both of the features 160and 161 into the elongate member 152 is that they cause the proximalsection of elongate member 152 to be self-centered onto the needle 130during the assembly process.

According to another manufacturing process, a plurality of elongatemembers 152 are initially deep drawn, or at least partially deep drawn,from a single metal sheet prior to the metal sheet being segmented forthe purpose of forming the first portions 110 of the needle guard 100.

FIGS. 20 through 23 illustrate a needle guard assembly 300 according toanother implementation. The needle guard 300 is similar to that ofneedle guard 100 described above except that arm segments 113 and 114have been modified to include arcuate recesses 313 and 314 that areconfigured to at least partially coincide with the curvature of theouter surface of elongate member 152. In one implementation one or bothof the recesses 313 and 314 are configured as half-circles that areshaped to coincide with the outer profile of the elongate member 152when the needle guard 300 is in the second axial position to protect thedistal end of needle 130. The circumferential edges of recesses 313 and314 rest against the outer surface of the elongate member 152 when theneedle guard 300 is in the second axial position (FIG. 23) to inhibitthe distal sections 107 and 108 of arms 101 and 102 from being urgedoutward away from covering the distal end of the needle 130 in the eventan improper force is applied to one or both of the arms.

As shown in FIG. 21, a method of fabricating a needle guard according tothe implementations disclosed and contemplated herein is to first stamp,cut or otherwise form the first portion 310 of the needle guard from aflat piece of resilient material as exemplified in FIG. 20. After thefirst portion 310 is formed the elongate member 152 may be positioned sothat the through passage 153 is axially aligned with the aperture 119 inbase 118. A fixture extending through the aperture 119 and through atleast a portion of the through passage 153 may be used to support theelongate member 152. According to other methods, the proximal end 154 ofthe elongate member 152 is provided with an outer reduced diametersegment 169 that extends through or is otherwise fitted to aperture 119to fully or partially support the elongate member 152 in a perpendicularrelationship with the first portion 310 as shown in FIG. 21. In oneimplementation, a reduced diameter annular ring located near theproximal end 154 of the elongate member 152 provides a means to snap fitthe proximal end of the elongate member into the base aperture 119 tosecure the elongate member 152 to the base 118. In otherimplementations, a slit or slot is provided in the base 118 that extendsfrom a side edge of the base to the aperture 119. In this manner theelongate member 152 may be provided with a reduced diameter annular ringportion near its proximal end 154 that permits the elongate member to beside loaded and fixed within the aperture 119 to effectuate anattachment of the elongate member 152 to the base 118. Upon the elongatemember 152 being properly supported on or attached to the first portion310, the first portion may be bent or partially bent to produce orpartially produce the requisite arm portions and hinges. At this stagethe first portion 310 and elongate member 152 may be loaded onto theneedle 130 with the first portion 310 being further bent (if required)and arranged on the needle 130 in a manner depicted in FIG. 22.

According to some implementations the first portion 310 and elongatemember 152 of needle guard 300 are unitarily constructed.

FIG. 24 shows a needle guard 350 according to another implementation.The needle guard 350 is similar to that of needle guard 300 describedabove except that arm 102 terminates just distal to recess 314 alongdotted line 320. In such an implementation the recess portion 314 iscontinually urged into contact with the outer surface of the elongatemember 152 with the distal section 107 of arm 101 situated to singularlycover the distal end 156 of the elongate member when the needle guard350 is situated in the second axial position on the needle 130. The arms101 and 102 of needle guards disclosed and contemplated herein maycomprise different types of features as exemplified in FIG. 24 where arm102 is comprises a recess 314 for abutting the outer surface of elongatemember 152 and where arm 101 comprises an elongate surface 113 forabutting the outer surface of the elongate member 152.

According to some implementations the first portion and elongate memberof the needle guard of FIG. 24 is unitarily constructed.

According to some implementations, as shown in FIGS. 25A, the elongatemember 152 comprises a resilient structure 170 having over-lappinglongitudinal portions 171 and 172 that are separable to form a temporarylongitudinal slit or slot along the length of the elongate member topermit it to be side-loaded onto the needle 130. FIG. 25A represents atop view of the elongate member 152. Upon the elongate member 152 beingside-loaded onto the needle shaft, the resilient structure 170 resumes,or substantially resumes, its initial configuration to completelysurround the circumference of the needle shaft 131. In oneimplementation the resilient structure 170 comprises an elastomermaterial having surface characteristics that facilitate the formation ofa seal along the over-lapping longitudinal portions 171 and 172 whentheir contact surfaces are brought into contact with one another. Inother implementations the resilient structure 170 comprises a metal. Insome implementations one or both of the over-lapping contact surfaces ofportions 171 and 172 is treated or otherwise coated with a substance toinduce the formation of a seal along the length of the elongate member152. In other implementations a seal is formed between the overlappingportions 171 and 172 by use of a sonic welding process or the like.

In other implementations, as illustrated in FIGS. 25B-D, the elongatemember 152 comprises one or more slits 175 a, 175 b that are separableto facilitate a side loading of the elongate member onto the shaft of aneedle. As with some of the implementations of FIG. 25A, the elongatemember 152 may comprise an elastomer material having characteristicsthat facilitate the formation of a seal between the mating surfaces ofthe slits when their contact surfaces are brought into contact with oneanother. In other implementations one or both of the contact surfaces ofslits is treated or otherwise coated with a substance to induce theformation of a seal along the length of the elongate member 152. Inother implementations a seal is formed between mating surfaces of theslits by use of a sonic welding process or the like.

FIGS. 26 through 31 illustrate a needle guard assembly 400 according toanother implementation. The needle guard 400 is similar to that ofneedle guard 100 described above except that arm segments 113 and 114have been modified to include formed portions 413 and 414 that areconfigured to at least partially coincide with the curvature of theouter surface of elongate member 152. A proximal section of the elongatemember 152 also includes a frustoconical portion 160 and a reduceddiameter portion 161 like that depicted in FIG. 15. In oneimplementation one or both of the proximal edges 415, 416 of formedportions 413, 414 are shaped to coincide with the outer profile of theelongate member 152 when the needle guard 400 is in the second axialposition to protect the distal end of needle 130. In practice the innersurfaces of the formed portions 413 and 414 rest against the outersurface of the elongate member 152 when the needle guard 400 is in thesecond axial position to inhibit the distal sections 107 and 108 of arms101 and 102 from being urged outward away from covering the distal endof the needle 130 in the event an improper force is applied to one orboth of the arms 101, 102 as illustrated in FIG. 29. FIG. 30 is anisometric view of the needle guard assembly 400 situated on the needle130 in the first axial position. FIG. 31 is an isometric view of theneedle guard assembly 400 situated on the needle 130 in the second axialposition.

According to some implementations, the first portion 410 and elongatemember 152 of needle guard 400 are unitarily constructed.

Like the implementation described above in conjunction with FIG. 24, itis appreciated that the needle guard 400 may be modified so that arm 102terminates at a location just distal to formed portion 414. In such animplementation the formed portion 414 is continually urged into contactwith the outer surface of the elongate member 152 with the distalsection 107 of arm 101 situated to singularly cover the distal end 156of the elongate member when the needle guard is situated in the secondaxial position on the needle 130.

It is important to note that many of the number of needle guard featuresdisclosed herein (both above and below) are interchangeable among thenumerous implementations disclosed and contemplated herein. For example,although some implementations disclose the use of features 113, 114 andother features 313, 314 and others 413, 414, it is appreciated that acombination of these features may be incorporated into a needle guardaccording to the inventions disclosed herein. Further, as an example,the variety of elongate members 152 and elongate features disclosedherein are interchangeable among the numerous implementations disclosedand contemplated herein.

FIGS. 32 through 34 illustrate a needle guard assembly 500 similar tothe needle guard assembly 300 described above except that the distal end502 of the elongate member 152 comprises an oblique orientation withrespect to the longitudinal axis of the elongate member and the distalsection 107 of arm 101 is angularly oriented to assume the obliqueorientation of the distal end 502 of the elongate member when the needleguard assembly 500 is in the second axial position as shown in FIG. 34.A proximal section of the elongate member 152 also includes afrustoconical portion 160 and a reduced diameter portion 161 like thatdepicted in FIG. 15. Distal section 107 is preferably configured toexert a force on the distal end 502 of the elongate member 152 when theneedle guard is in the second axial position. The lip 504 located at thedistal end of section 107 is also oriented in a downward facing positionand is situated to traverse the beveled distal opening of the elongatemember 152 to provide a mechanical stop that inhibits the distal armsection 107 from separating from the distal end 502 of the elongatemember when a compressive force or “pinch” is applied to one or both ofarms 101 and 102.

According to some implementations the first portion and elongate member152 of needle guard 500 are unitarily constructed.

A downward facing lip may be provided at the distal end of the distalsections 107 in the various implementations disclosed herein to inhibitthe distal arm section 107 from separating from the distal end of theelongate member 152 when a compressive force or “pinch” is applied toone or both of arms 101 and 102. In some implementations the distal endof the elongate member 152 is provided with an indentation or kerf tointerlock with a lip provided at a distal end of section 107.

FIGS. 35 through 37 illustrate a needle guard 600 according to anotherimplementation. The needle guard comprises a first portion 610 with anelongate member 652 integrated therein. In one implementation the firstportion 610 includes first and second arms 601 and 602, respectively,that extend from opposite sides of a base 618. The first portion ispreferably fabricated from a single piece of resilient material that isbent to form the base 618, arms 601, 602 and distal arm sections 607,608. An aperture in the base 618 (not shown) is sized to receive aproximal portion 136 of the needle 130 and to guide the needle guardalong the needle shaft as it transitions from a first axial position (asshown in FIGS. 35 and 36) to a second axial position to protect thedistal end 134 of the needle (as shown in FIG. 37). The arms 601, 602are hinged at the base 618 and are configured to assume an abuttingrelationship with the outer surface of the needle 130 when the needleguard 600 is situated in a first axial position with the distal end 134of the needle is unprotected. An elongate member 652 having proximal anddistal ends 654 and 656, respectively, is provided with an internalthrough passage 653 that extends between the two ends. The needle 130comprises a proximal shaft portion 136 and a flared distal shaft portion138 of increasing diameter. In use, the elongate member 652 is situatedto reside in the first portion 610 between the base 618 and the distalarm section 608. In one implementation the aperture in base 618 is sizedto engage with flared distal shaft portion 118 to stop the needle guard600 in the second axial position as depicted in FIG. 37 with theentirety of the internal passage 653 of the elongate member 652 having adiameter sufficient to be advanced so that the distal end 656 of theelongate member extends to or past the distal tip of the needle. Inanother implementation the proximal end of the elongate member 652 isprovided with a reduced internal diameter portion that acts to stop theneedle guard in the second axial position. In another implementation asleeve or bushing is situated at the proximal end 654 of the elongatemember 652 and includes an internal bore with diameter sufficient to actas the second axial position stop.

As illustrated in FIG. 37, substantially coincident with the distal end656 of the elongate member 652 situated to cover the entirety of thedistal end 134 of the needle 130, arms 601 and 602 disengage from theneedle shaft and are urged inward by stored energy to cover the distalend of the elongate member. According to one implementation, distal armsection 608 is hinged at location 620 to provide a downward/proximallyacting force on the distal end 656 of elongate member 652. In oneimplementation arms 601 and 602 are provided with protrusions 619 and620 that function to interact with one or more internal features of acatheter hub to releasably secure the needle guard 600 within thecatheter hub in a manner similarly described with respect to FIG. 38.

According to some implementations the first portion and elongate member652 of needle guard 600 are unitarily constructed.

As discussed above, FIG. 38 is a side view of a safety intravenouscatheter assembly 700 in a ready to use operative position according toone implementation. Assembly 700 includes a needle 130 with a sharpeneddistal tip 134 with an internal lumen extending from a proximal end 140to the tip 134. A change in profile 132 on the needle shaft functions tostop the needle guard 100 in the second axial position as previouslydescribed. A proximal end portion of the needle 130 is attached to aneedle hub 704 having proximal protrusions 706 for attaching a male luerfitting. The proximal end 140 of the needle being situated in aflashback chamber 708 of the needle hub 704. As previously discussed,the needle guard 100 is releasable secured in the catheter hub 702 bythe engagement of protrusions 117 and 116 with a feature or features 703situated on the inner wall of the catheter hub. The proximal end of thecatheter hub 702 is operatively engaged with the distal end of theneedle hub 704. A tubular catheter 710 extends distally from the distalend of the catheter hub 702 in coaxial relationship with needle 130 andterminates proximal to the needle tip 134 so that the needle tip isexposed for puncturing a blood vessel and introducing the catheter 710.In use, upon the catheter 710 being properly introduced into the vesselof a patient, the needle hub 704 is pulled proximally to retract theneedle tip 134 from the patient and into the needle tip guard 100. Asthe needle is withdrawn, the needle guard 100 is secured within theneedle hub 702 by the outward force exerted by protrusions 117 and 116.The location of the change in profile 132 on the needle 130 incombination with the dimensional characteristics of the needle guard 100result in the distal tip 134 being fully housed within the elongatemember 152 substantially coincident with the change in profile 132 beingstopped on the needle guard. Upon the distal tip 134 entering the distalend 156 of the elongate member 152, the distal arm segments 107 and 108disengage the needle shaft and are urged inward to cover the distal end156 of the elongate member by stored energy in the arms 101 and 102. Atthe same time protrusions 107 and 108 disengage with the catheter hub702 to permit the needle guard 100 and needle 130 to be fully removedfrom the catheter hub 702.

FIGS. 39 and 40 illustrate an intravenous catheter assembly 800according to another implementation. Assembly 800 is similar to that ofassembly 700 discussed above. A difference lies in the manner in whichthe needle guard 100 is releasably secured within the catheter hub 802.In the assembly 800, in lieu of the use of protrusion 117, 118 formed onarms 101, 102, resilient tabs 810 and 811 situated at or near the baseof the needle guard 100 protrude outward to engage one or more features803 of the inner wall of the catheter hub 802. The outer engagingsurfaces of tabs 810 and 811 are preferably arcuate to coincide with thecurvature of the inner wall of the catheter hub 802. The one or morefeatures 803 may comprise a recess, undercut, void, groove, protrudingfeature, etc., configured either annularly or in segments about theinner wall. The resilient tabs 810 and 811 are configured to exert anoutward force to cause the engaging surfaces to engage with the one ormore features 803 when the assembly 800 is in the ready position orduring the withdrawal of the needle 130 into the needle guard 100. Theengagement force of tabs 810 and 811 is sufficiently low to permit thetabs to disengage from the one or more features 803 (see FIG. 40) when aproximal force is applied to the needle guard upon the change in profile132 of the needle engaging needle guard stop.

FIG. 41 illustrates a needle guard assembly 900 situated in a protectiveposition on a Huber needle, the Huber needle being characterized by achange in axis or bend near the distal end of the needle 190. The needleguard assembly 900 is in many respects similar to some of theimplementations disclosed and described above except that the internalpassage extending through the elongate member 952 is configured in sucha way that permits the distal portion 958 of the elongate member tomaneuver around the change in axis and to cant as the needle 190 isretracted into a protected position within the elongate member 952. Inone implementation a proximal end section 960 of the elongate member 952is provided with a reduced inner diameter segment of an appropriatelength that stops the needle guard on the change in axis. In otherimplementations, a sleeve of sufficient length with a reduced innerdiameter is attached to or otherwise coupled to the proximal end ofelongate member 952. In other implementations a change in profile orenlargement is situated proximal to the change in axis to act as thestop.

Numerous exemplary implementations have been disclosed and describedherein. It is to be appreciated however, that the present invention isin no way to be construed as to being limited to these examples.

What is claimed is:
 1. An IV catheter assembly comprising: a catheterhub comprising a hollow body having a proximal end and a distal end, thehollow body defining an interior space; a catheter having a proximal endand a distal end, the proximal end of the catheter coupled to theproximal end of the catheter hub; a needle having a needle shaft and adistal tip, the needle moveable between a ready position and a retractedposition, in the ready position the distal tip of the needle extendingdistally from the distal end of the catheter, in the retracted positionthe distal tip of the needle residing in a position proximal to theproximal end of the catheter, the needle shaft having a change inprofile; and a needle guard comprising an elongate arm that extendsdistally from a base, the base having an aperture formed therein, theneedle guard slideably mounted on the needle shaft with the needle shaftpassing through the aperture formed in the base, the aperture sized sothat a portion of the base circumscribing the aperture engages with thechange in profile of the needle shaft to limit a proximal movement ofthe needle with respect to the needle guard, the elongate arm comprisinga proximal section and a distal section, the elongate arm extending fromthe base and intersecting the needle shaft along a first portion of theelongate arm located between the proximal and distal sections so that asegment of the distal section of the elongate arm is urged against aside of the needle shaft when the needle is in the ready position, theneedle guard further comprising an elongate member having a throughpassage extending between an open proximal end and an open distal end ofthe elongate member, the needle shaft extending through the open distalend of the elongate member when the needle is in the ready position, theelongate member extending distally from a position at or near the baseand slideable alongside the needle shaft as the needle is moved betweenthe ready position and the retracted position, when the needle is in theready position and the retracted position the elongate member extendsthrough a passage in the first portion of the elongate arm.
 2. An IVcatheter assembly according to claim 1, wherein the elongate member hasa length such that substantially coincident with the change in profileengaging the portion of the base circumscribing the aperture in the basethe entirety of the distal tip of the needle is positioned to residewithin the through passage of the elongate member and the distal sectionof the elongate arm disengages with the needle shaft and moves radiallyinward to at least partially lie over the distal end of the elongatemember.
 3. An IV catheter assembly according to claim 1, wherein theelongate member is sufficiently rigid so that the length of the elongatemember remains the same when the needle is in the ready and retractedpositions.
 4. An IV catheter assembly according to claim 1, wherein thedistal section of the elongate arm comprises a first wall segment havinga distal end, the first wall segment and first portion of the elongatearm disposed at different angular orientations with respect to theneedle, the first wall segment angled inwardly toward the needle, thedistal end of the first wall segment urged against the side of theneedle shaft when the needle is in the ready position, the distal end ofthe first wall segment configured to disengage the needle shaftsubstantially coincident with the change in profile engaging the portionof the base circumscribing the aperture in the base so that the firstwall segment at least partially lies over the distal end of the elongatemember.
 5. An IV catheter assembly according to claim 1, wherein theelongate member is attached to the base.
 6. An IV catheter assemblyaccording to claim 1, wherein the elongate member is not attached to thebase.
 7. An IV catheter assembly according to claim 1, wherein the baseand the elongate arm comprise a unitary structure.
 8. An IV catheterassembly according to claim 1, wherein the base, the elongate arm andthe elongate member comprise a unitary structure.
 9. An IV catheterassembly according to claim 1, wherein the elongate member completelycircumscribes the needle shaft.
 10. An IV catheter assembly according toclaim 1, wherein the elongate member and the base comprise a unitarystructure.
 11. An IV catheter assembly according to claim 2, wherein atleast a part of the first portion or at least a part of the distalsection of the elongate arm is configured to rest against an externalsurface of the elongate member upon the elongate arm disengaging withthe needle shaft.
 12. An IV catheter assembly comprising: a catheter hubcomprising a hollow body having a proximal end and a distal end, thehollow body defining an interior space; a catheter having a proximal endand a distal end, the proximal end of the catheter coupled to theproximal end of the catheter hub; a needle having a needle shaft and adistal tip, the needle moveable between a ready position and a retractedposition, in the ready position the distal tip of the needle extendingdistally from the distal end of the catheter, in the retracted positionthe distal tip of the needle residing in a position proximal to theproximal end of the catheter, the needle shaft having a change inprofile; and a needle guard comprising first and second arms that eachextends distally from a base, the base having an aperture formedtherein, the needle guard slideably mounted on the needle shaft with theneedle shaft passing through the aperture formed in the base, theaperture sized so that a portion of the base circumscribing the apertureengages with the change in profile of the needle shaft to limit aproximal movement of the needle with respect to the needle guard, eachof the first and second arms comprising a proximal section, a distalsection and a first portion located between the proximal and distalsections, the first and second arms extending from different positionsof the base and intersecting one another along their first portions sothat a segment of each of the distal sections of the first and secondarms resides and is urged against opposite sides of the needle shaftwhen the needle is in the ready position, the needle guard furthercomprising an elongate member having a through passage extending betweenan open proximal end and an open distal end of the elongate member, theneedle shaft extending through the open distal end of the elongatemember when the needle is in the ready position, the elongate memberextending distally from a position at or near the base and slideablealongside the needle shaft as the needle is moved between the readyposition and the retracted position, when the needle is in the readyposition and the retracted position the elongate member extends througha passage in the first portion of each of the first and second arms. 13.An IV catheter assembly according to claim 12, wherein the elongatemember has a length such that substantially coincident with the changein profile engaging the portion of the base circumscribing the aperturein the base the entirety of the distal tip of the needle is positionedto reside within the through passage of the elongate member and thedistal section of at least one of the first and second arms disengageswith the needle shaft and moves radially inward to at least partiallylie over the distal end of the elongate member.
 14. An IV catheterassembly according to claim 12, wherein the elongate member issufficiently rigid so that the length of the elongate member remains thesame when the needle is in the ready and retracted positions.
 15. An IVcatheter assembly according to claim 12, wherein the distal section ofthe first arm comprises a first wall segment having a distal end, thefirst wall segment and first portion of the first arm disposed atdifferent angular orientations with respect to the needle, the firstwall segment angled inwardly toward the needle, the distal section ofthe second arm comprises a second wall segment having a distal end, thesecond wall segment and first portion of the second arm disposed atdifferent angular orientations with respect to the needle, the secondwall segment angled inwardly toward the needle, the distal ends of thefirst and second wall segments urged against opposite sides of theneedle shaft when the needle is in the ready position, the distal end ofthe first wall segment configured to disengage with the needlesubstantially coincident with the change in profile engaging the portionof the base circumscribing the aperture in the base so that the firstwall segment at least partially lies over the distal end of the elongatemember, the distal end of the second wall segment configured todisengage with the needle substantially coincident with the change inprofile engaging the portion of the base circumscribing the aperture inthe base to be positioned distal to and overlapping with the first wallsegment.
 16. An IV catheter assembly according to claim 12, wherein theelongate member is attached to the base.
 17. An IV catheter assemblyaccording to claim 12, wherein the elongate member is not attached tothe base.
 18. An IV catheter assembly according to claim 12, wherein thebase and the first and second arms comprise a unitary structure.
 19. AnIV catheter assembly according to claim 12, wherein the elongate memberand the base comprise a unitary structure.
 20. An IV catheter assemblyaccording to claim 12, wherein the base, the elongate member and thefirst and second arms comprise a unitary structure.
 21. An IV catheterassembly according to claim 13, wherein at least a part of the firstportion or at least a part of the distal section of the first arm isconfigured to rest against an external surface of the elongate memberupon the first arm disengaging with the needle shaft.
 22. An IV catheterassembly according to claim 13, wherein at least a part of the firstportion or at least a part of the distal section of each of the firstand second arms is configured to rest against an external surface of theelongate member upon the first and second arms disengaging with theneedle shaft.
 23. An IV catheter assembly comprising: a catheter hubcomprising a hollow body having a proximal end and a distal end, thehollow body defining an interior space; a catheter having a proximal endand a distal end, the proximal end of the catheter coupled to theproximal end of the catheter hub; a needle having a needle shaft and adistal tip, the needle moveable between a ready position and a retractedposition, in the ready position the distal tip of the needle extendingdistally from the distal end of the catheter, in the retracted positionthe distal tip of the needle residing in a position proximal to theproximal end of the catheter, the needle shaft having a change inprofile; and a needle guard comprising an elongate arm that extendsdistally from a base, the base having an aperture formed therein, theneedle guard slideably mounted on the needle shaft with the needle shaftpassing through the aperture formed in the base, the elongate armcomprising a proximal section and a distal section, the elongate armextending from the base and intersecting the needle shaft along a firstportion of the elongate arm located between the proximal and distalsections so that the distal section of the elongate arm is urged againsta side of the needle shaft when the needle is in the ready position, theneedle guard further comprising an elongate member having a throughpassage extending between an open proximal end and an open distal end ofthe elongate member, the needle shaft extending through the open distalend of the elongate member when the needle is in the ready position, theelongate member extending distally from a position at or near the baseand slideable alongside the needle shaft as the needle is moved betweenthe ready position and the retracted position, when the needle is in theready position and the retracted position the elongate member extendsthrough a passage in the first portion of the elongate arm, the throughpassage of the elongate member having an area of reduced cross-sectionat a location along the length of the elongate member, the area ofreduced cross-section sized so that a portion of an inner wall of theelongate member engages with the change in profile of the needle shaftto limit a proximal movement of the needle with respect to the needleguard.
 24. An IV catheter assembly according to claim 23, wherein theelongate member has a length such that substantially coincident with thechange in profile engaging the inner wall of the elongate member theentirety of the distal tip of the needle is positioned to reside withinthe through passage of the elongate member and the distal section of theelongate arm disengages with the needle shaft and moves radially inwardto at least partially lie over the distal end of the elongate member.25. An IV catheter assembly according to claim 23, wherein the elongatemember is sufficiently rigid so that the length of the elongate memberremains the same when the needle is in the ready and retracted positions26. An IV catheter assembly according to claim 23, wherein the distalsection of the elongate arm comprises a first wall segment having adistal end, the first wall segment and first portion of the elongate armdisposed at different angular orientations with respect to the needle,the first wall segment angled inwardly toward the needle, the distal endof the first wall segment urged against the side of the needle shaftwhen the needle is in the ready position, the distal end of the firstwall segment configured to disengage the needle shaft substantiallycoincident with the change in profile engaging the inner wall of theelongate member so that the first wall segment at least partially liesover the distal end of the elongate member.
 27. An IV catheter assemblyaccording to claim 23, wherein the elongate member is attached to thebase.
 28. An IV catheter assembly according to claim 23, wherein theelongate member is not attached to the base.
 29. An IV catheter assemblyaccording to claim 23, wherein the base and the elongate arm comprise aunitary structure.
 30. An IV catheter assembly according to claim 23,wherein the base, the elongate arm and the elongate member comprise aunitary structure.
 31. An IV catheter assembly according to claim 23,wherein the elongate member completely circumscribes the needle shaft.32. An IV catheter assembly according to claim 23, wherein the base andelongate member comprise a unitary structure.
 33. An IV catheterassembly according to claim 24, wherein at least a part of the firstportion or at least a part of the distal section of the elongate arm isconfigured to rest against an external surface of the elongate memberupon the elongate arm disengaging with the needle shaft.
 34. An IVcatheter assembly comprising: a catheter hub comprising a hollow bodyhaving a proximal end and a distal end, the hollow body defining aninterior space; a catheter having a proximal end and a distal end, theproximal end of the catheter coupled to the proximal end of the catheterhub; a needle having a needle shaft and a distal tip, the needlemoveable between a ready position and a retracted position, in the readyposition the distal tip of the needle extending distally from the distalend of the catheter, in the retracted position the distal tip of theneedle residing in a position proximal to the proximal end of thecatheter, the needle shaft having a change in profile; and a needleguard comprising first and second arms that each extends distally from abase, the base having an aperture formed therein, the needle guardslideably mounted on the needle shaft with the needle shaft passingthrough the aperture formed in the base, each of the first and secondarms comprising a proximal section, a distal section and a first portionlocated between the proximal and distal sections, the first and secondarms extending from different positions of the base and intersecting oneanother along their first portions so that the distal sections of thefirst and second arms reside and are urged against opposite sides of theneedle shaft when the needle is in the ready position, the needle guardfurther comprising an elongate member having a through passage extendingbetween an open proximal end and an open distal end of the elongatemember, the needle shaft extending through the open distal end of theelongate member when the needle is in the ready position, the elongatemember extending distally from a position at or near the base andslideable alongside the needle shaft as the needle is moved between theready position and the retracted position, when the needle is in theready position and the retracted position the elongate member extendsthrough a passage in the first portion of each of the first and secondarms, the through passage of the elongate member having an area ofreduced cross-section at a location along the length of the elongatemember, the area of reduced cross-section sized so that a portion of aninner wall of the elongate member engages with the change in profile ofthe needle shaft to limit a proximal movement of the needle with respectto the needle guard.
 35. An IV catheter assembly according to claim 34,wherein the elongate member has a length such that substantiallycoincident with the change in profile engaging the inner wall of theelongate member the entirety of the distal tip of the needle ispositioned to reside within the through passage of the elongate memberand the distal section of at least one of the first and second armsdisengages with the needle shaft and moves radially inward to at leastpartially lie over the distal end of the elongate member.
 36. An IVcatheter assembly according to claim 34, wherein the elongate member issufficiently rigid so that the length of the elongate member remains thesame when the needle is in the ready and retracted positions.
 37. An IVcatheter assembly according to claim 34, wherein the distal section ofthe first arm comprises a first wall segment having a distal end, thefirst wall segment and first portion of the first arm disposed atdifferent angular orientations with respect to the needle, the firstwall segment angled inwardly toward the needle, the distal section ofthe second arm comprises a second wall segment having a distal end, thesecond wall segment and first portion of the second arm disposed atdifferent angular orientations with respect to the needle, the secondwall segment angled inwardly toward the needle, the distal ends of thefirst and second wall segments urged against opposite sides of theneedle shaft when the needle is in the ready position, the distal end ofthe first wall segment configured to disengage with the needlesubstantially coincident with the change in profile engaging the innerwall of the elongate member so that the first wall segment at leastpartially lies over the distal end of the elongate member, the distalend of the second wall segment configured to disengage with the needlesubstantially coincident with the change in profile engaging the innerwall of the elongate member to be positioned distal to and overlappingwith the first wall segment.
 38. An IV catheter assembly according toclaim 34, wherein the elongate member is attached to the base.
 39. An IVcatheter assembly according to claim 34, wherein the elongate member isnot attached to the base.
 40. An IV catheter assembly according to claim34, wherein the base and the first and second arms comprise a unitarystructure.
 41. An IV catheter assembly according to claim 34, whereinthe elongate member and base comprise a unitary structure.
 42. An IVcatheter assembly according to claim 34, wherein the base, the elongatemember and the first and second arms comprise a unitary structure. 43.An IV catheter assembly according to claim 35, wherein at least a partof the first portion or at least a part of the distal section of thefirst arm is configured to rest against an external surface of theelongate member upon the first arm disengaging with the needle shaft.44. An IV catheter assembly according to claim 35, wherein at least apart of the first portion or at least a part of the distal section ofeach of the first and second arms is configured to rest against anexternal surface of the elongate member upon the first and second armsdisengaging with the needle shaft.